Cut-out for electric circuits.



PATENTED NOV. 8, 1903.

E. M. NORTH.

CUT-OUT FOR ELECTRIC CIRCUITS.

APPLICATION FILED JAN. 21. 1903.

N0 MODEL.

m? uM fi n v I g m Patented November 3, 1903.

PATENT OFFICE.

EDGAR MOSHER NORTH, OF BROOKLYN, NEW' YORK.

CUT-OUT FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 742,895, dated November3, 1903.

Application filed January 21, 1903. Serial No. 140,047. (No model.)

To all whom it may concern.-

Be it known that I, EDGAR MosHER NORTH, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York, haveinvented certain new and useful Improvements in Cut-Outs for ElectricCircuits, of which thefollowingis a specification.

The object of this invention is to provide a cheap, simple, andefficient automatic cut-out for electric circuits and it consists of apair of bars joined together slightly out of alinement with each otherand connected at the joint with a link at right angles thereto, saidlink being connected with a lever, the opposite end of this lever beingin contact with the bindingpost of a resistan ce-coil. The aforesaidbars, together with the link and lever, form the conductors for thecurrent, and when same becomes excessive the jointed bars are heated up,thus expanding them and throwing the circuit into a resistance-coil andcutting the said bars out of the circuit, all of which will now be setforth in detail.

In the drawings, Figure 1 is a top or plan View of the cut-outapparatus, showing the normal relation of the parts; Fig. 2, an edgeview of the same, and Fig. 3 a cross-section on line 3 of Fig. 1.

In constructing the apparatus I provide a base 4, of insulatingmaterial, at each end of which is a binding-post. The binding-post 5 atone end is attached to a metal plate 6, to which plate also is hingedone end of a bar 7. At the otherend of the base 4is a bindingpost 8,secured to an insulated plate 9, and below this plate is another plate10, to which the end of a bar 11 is hinged, this bar being similar tobar 7 and jointed thereto at 12 and in such a position that normallythese bars are slightly out of alinement with each other.

Below the bar 7 and parallel therewith is a lever 13, hinged at one endto a post let and having its produced end 15 connected with the jointedbars 7 11 at their hinged point 12 by means of a link 16. Beyond thislink the end 15 is bent downwardly or toward the base 4 and is incontact with two plates 17 18, the former of which is in permanentelectrical connection with the plate 6 by means of a wire 19, and thelatter plate 18 having a permanent electrical connection with the plate10 by means of a wire 20. These contactplates 17 18 are slightlyseparated from each other, as shown, so there is no connectionelectrically between the conductors 19 20.

The free end of the lever 13 has a contactface 21, which travels overthe contact-posts 22 of the resistance-coil 23. When the apparatus is inits normal position, as shown in Fig. 1, the contact-face 21 is inengagement with a plate 25, which is connected up with the plate 9 bymeans of a conductor 26. It will thus be seen that normally the currententers at the binding-post 5 and traverses the bars 7 11, plate 10,conductor 20, plate 18, lever 15 13, plate 25, and conductor 26 to thebinding-post 8. It now the current over theline should be in excess ofthe requirements, the bars 7 11, being of such metal as to carry thepredetermined load, will heat up and expand, thus causing them to moveupwardly at their jointed ends,carryin g therewith the link 16 andcausing the end of the lever 13 to move downwardly, cutting out theelectric circuit through the plate 25 and throwing in theresistance-coils 23. Should the cur-- rent increase and the bars stillfurther expand, it is desirable that the bars 7 11 should be cut out ofthe circuit, and by reference to Fig. 1 it will be seen that when thecontactface 21 of the lever 13 has reached the third contact-post of theresistance-coil the other end 15 of the lever has moved from the plate18 to plate 17, as shown by dotted lines 27, thus breaking the circuitthrough the bars and diverting it entirely through the resistance-coils.

It is desirable that the resistance of the bars 7 11 should beapproximately equal to the resistance in the coils 23 up to the pointwhere the bars are eventually cut out of the circuit.

It is obvious that when the contact-face 21 has passed over all theposts 22 the circuit will be broken and reestablished automatically bythe contracting of the bars 7 11.

' The expansion-bars are very sensitive, and it is found that thecurrent will at times heat them up so rapidly as to carry thecontactface 21 of the lever 13 down to the lower contact 22 or beyond,so that-temporarily in such cases the current is cut out entirely.

The object in cutting out the expansionbars 7 11 as soon as the contact21 has passed 2 v 'mases the second contact 22 is to permit the bars tocool off, and thus permit them to contract and reestablish the currenttherethrough.

What I claim as new is 1. A cut-out for electric circuits comprising apair of bars in an electric circuit, jointed together centrally and outof alinement with each other, a resistance-coil and means between saidbars and resistance-coil for cutting the bars out of the circuit anddiverting the current to the resistance-coil.

2. A cut-out for electric circuits, comprising apair of bars in anelectric circuit, jointed together centrally and out of alinement witheach other, a resistance-coil, normally out of the circuit, and meansbetween said bars and resistance-coil for temporarily diverting thecurrent from said bars to the resistance-coils, and for entirely cuttingout the current from said bars, substantially as set forth.

3. A cut-out for electric circuits comprising a base, with abinding-post at each end, a

pair of bars centrally jointed and slightly out of alinenient With eachother, secured to the base and electrically connected at one end withthe positive binding-post, the opposite end of said bars havingelectrical connection with a contact-plate on the base, a swinginglever, connected with the jointed bars, and operatively in engagementwith the contactplate on the base, and an adjoining contactplate on thebase connected up with the main circuit, and operatively brought intocontact with the swinging lever, a resistance-coil in engagement withthe swinging lever, and electrical connection between the resistancecoiland the negative binding-post, as set forth.

In testimony whereof I allix my signature in presence of two witnesses.

EDGAR MOSHER NORTH. Witnesses:

J. I. BERLIN, O. L. DELANY.

